summaryrefslogtreecommitdiffstats
path: root/include/uapi/linux/nilfs2_ondisk.h
blob: c23f91ae5fe8b17c6176c91027b63840dd1c2a0b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
/* SPDX-License-Identifier: LGPL-2.1+ WITH Linux-syscall-note */
/*
 * nilfs2_ondisk.h - NILFS2 on-disk structures
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 */
/*
 *  linux/include/linux/ext2_fs.h
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#ifndef _LINUX_NILFS2_ONDISK_H
#define _LINUX_NILFS2_ONDISK_H

#include <linux/types.h>
#include <linux/magic.h>
#include <asm/byteorder.h>

#define NILFS_INODE_BMAP_SIZE	7

/**
 * struct nilfs_inode - structure of an inode on disk
 * @i_blocks: blocks count
 * @i_size: size in bytes
 * @i_ctime: creation time (seconds)
 * @i_mtime: modification time (seconds)
 * @i_ctime_nsec: creation time (nano seconds)
 * @i_mtime_nsec: modification time (nano seconds)
 * @i_uid: user id
 * @i_gid: group id
 * @i_mode: file mode
 * @i_links_count: links count
 * @i_flags: file flags
 * @i_bmap: block mapping
 * @i_xattr: extended attributes
 * @i_generation: file generation (for NFS)
 * @i_pad: padding
 */
struct nilfs_inode {
	__le64	i_blocks;
	__le64	i_size;
	__le64	i_ctime;
	__le64	i_mtime;
	__le32	i_ctime_nsec;
	__le32	i_mtime_nsec;
	__le32	i_uid;
	__le32	i_gid;
	__le16	i_mode;
	__le16	i_links_count;
	__le32	i_flags;
	__le64	i_bmap[NILFS_INODE_BMAP_SIZE];
#define i_device_code	i_bmap[0]
	__le64	i_xattr;
	__le32	i_generation;
	__le32	i_pad;
};

#define NILFS_MIN_INODE_SIZE		128

/**
 * struct nilfs_super_root - structure of super root
 * @sr_sum: check sum
 * @sr_bytes: byte count of the structure
 * @sr_flags: flags (reserved)
 * @sr_nongc_ctime: write time of the last segment not for cleaner operation
 * @sr_dat: DAT file inode
 * @sr_cpfile: checkpoint file inode
 * @sr_sufile: segment usage file inode
 */
struct nilfs_super_root {
	__le32 sr_sum;
	__le16 sr_bytes;
	__le16 sr_flags;
	__le64 sr_nongc_ctime;
	struct nilfs_inode sr_dat;
	struct nilfs_inode sr_cpfile;
	struct nilfs_inode sr_sufile;
};

#define NILFS_SR_MDT_OFFSET(inode_size, i)  \
	((unsigned long)&((struct nilfs_super_root *)0)->sr_dat + \
			(inode_size) * (i))
#define NILFS_SR_DAT_OFFSET(inode_size)     NILFS_SR_MDT_OFFSET(inode_size, 0)
#define NILFS_SR_CPFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 1)
#define NILFS_SR_SUFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 2)
#define NILFS_SR_BYTES(inode_size)	    NILFS_SR_MDT_OFFSET(inode_size, 3)

/*
 * Maximal mount counts
 */
#define NILFS_DFL_MAX_MNT_COUNT		50      /* 50 mounts */

/*
 * File system states (sbp->s_state, nilfs->ns_mount_state)
 */
#define NILFS_VALID_FS			0x0001  /* Unmounted cleanly */
#define NILFS_ERROR_FS			0x0002  /* Errors detected */
#define NILFS_RESIZE_FS			0x0004	/* Resize required */

/*
 * Mount flags (sbi->s_mount_opt)
 */
#define NILFS_MOUNT_ERROR_MODE		0x0070  /* Error mode mask */
#define NILFS_MOUNT_ERRORS_CONT		0x0010  /* Continue on errors */
#define NILFS_MOUNT_ERRORS_RO		0x0020  /* Remount fs ro on errors */
#define NILFS_MOUNT_ERRORS_PANIC	0x0040  /* Panic on errors */
#define NILFS_MOUNT_BARRIER		0x1000  /* Use block barriers */
#define NILFS_MOUNT_STRICT_ORDER	0x2000  /*
						 * Apply strict in-order
						 * semantics also for data
						 */
#define NILFS_MOUNT_NORECOVERY		0x4000  /*
						 * Disable write access during
						 * mount-time recovery
						 */
#define NILFS_MOUNT_DISCARD		0x8000  /* Issue DISCARD requests */


/**
 * struct nilfs_super_block - structure of super block on disk
 */
struct nilfs_super_block {
/*00*/	__le32	s_rev_level;		/* Revision level */
	__le16	s_minor_rev_level;	/* minor revision level */
	__le16	s_magic;		/* Magic signature */

	__le16  s_bytes;		/*
					 * Bytes count of CRC calculation
					 * for this structure. s_reserved
					 * is excluded.
					 */
	__le16  s_flags;		/* flags */
	__le32  s_crc_seed;		/* Seed value of CRC calculation */
/*10*/	__le32	s_sum;			/* Check sum of super block */

	__le32	s_log_block_size;	/*
					 * Block size represented as follows
					 * blocksize =
					 *     1 << (s_log_block_size + 10)
					 */
	__le64  s_nsegments;		/* Number of segments in filesystem */
/*20*/	__le64  s_dev_size;		/* block device size in bytes */
	__le64	s_first_data_block;	/* 1st seg disk block number */
/*30*/	__le32  s_blocks_per_segment;   /* number of blocks per full segment */
	__le32	s_r_segments_percentage; /* Reserved segments percentage */

	__le64  s_last_cno;		/* Last checkpoint number */
/*40*/	__le64  s_last_pseg;		/* disk block addr pseg written last */
	__le64  s_last_seq;             /* seq. number of seg written last */
/*50*/	__le64	s_free_blocks_count;	/* Free blocks count */

	__le64	s_ctime;		/*
					 * Creation time (execution time of
					 * newfs)
					 */
/*60*/	__le64	s_mtime;		/* Mount time */
	__le64	s_wtime;		/* Write time */
/*70*/	__le16	s_mnt_count;		/* Mount count */
	__le16	s_max_mnt_count;	/* Maximal mount count */
	__le16	s_state;		/* File system state */
	__le16	s_errors;		/* Behaviour when detecting errors */
	__le64	s_lastcheck;		/* time of last check */

/*80*/	__le32	s_checkinterval;	/* max. time between checks */
	__le32	s_creator_os;		/* OS */
	__le16	s_def_resuid;		/* Default uid for reserved blocks */
	__le16	s_def_resgid;		/* Default gid for reserved blocks */
	__le32	s_first_ino;		/* First non-reserved inode */

/*90*/	__le16  s_inode_size;		/* Size of an inode */
	__le16  s_dat_entry_size;       /* Size of a dat entry */
	__le16  s_checkpoint_size;      /* Size of a checkpoint */
	__le16	s_segment_usage_size;	/* Size of a segment usage */

/*98*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
/*A8*/	char	s_volume_name[80];	/* volume name */

/*F8*/	__le32  s_c_interval;           /* Commit interval of segment */
	__le32  s_c_block_max;          /*
					 * Threshold of data amount for
					 * the segment construction
					 */
/*100*/	__le64  s_feature_compat;	/* Compatible feature set */
	__le64  s_feature_compat_ro;	/* Read-only compatible feature set */
	__le64  s_feature_incompat;	/* Incompatible feature set */
	__u32	s_reserved[186];	/* padding to the end of the block */
};

/*
 * Codes for operating systems
 */
#define NILFS_OS_LINUX		0
/* Codes from 1 to 4 are reserved to keep compatibility with ext2 creator-OS */

/*
 * Revision levels
 */
#define NILFS_CURRENT_REV	2	/* current major revision */
#define NILFS_MINOR_REV		0	/* minor revision */
#define NILFS_MIN_SUPP_REV	2	/* minimum supported revision */

/*
 * Feature set definitions
 *
 * If there is a bit set in the incompatible feature set that the kernel
 * doesn't know about, it should refuse to mount the filesystem.
 */
#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT	0x00000001ULL

#define NILFS_FEATURE_COMPAT_SUPP	0ULL
#define NILFS_FEATURE_COMPAT_RO_SUPP	NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
#define NILFS_FEATURE_INCOMPAT_SUPP	0ULL

/*
 * Bytes count of super_block for CRC-calculation
 */
#define NILFS_SB_BYTES  \
	((long)&((struct nilfs_super_block *)0)->s_reserved)

/*
 * Special inode number
 */
#define NILFS_ROOT_INO		2	/* Root file inode */
#define NILFS_DAT_INO		3	/* DAT file */
#define NILFS_CPFILE_INO	4	/* checkpoint file */
#define NILFS_SUFILE_INO	5	/* segment usage file */
#define NILFS_IFILE_INO		6	/* ifile */
#define NILFS_ATIME_INO		7	/* Atime file (reserved) */
#define NILFS_XATTR_INO		8	/* Xattribute file (reserved) */
#define NILFS_SKETCH_INO	10	/* Sketch file */
#define NILFS_USER_INO		11	/* Fisrt user's file inode number */

#define NILFS_SB_OFFSET_BYTES	1024	/* byte offset of nilfs superblock */

#define NILFS_SEG_MIN_BLOCKS	16	/*
					 * Minimum number of blocks in
					 * a full segment
					 */
#define NILFS_PSEG_MIN_BLOCKS	2	/*
					 * Minimum number of blocks in
					 * a partial segment
					 */
#define NILFS_MIN_NRSVSEGS	8	/*
					 * Minimum number of reserved
					 * segments
					 */

/*
 * We call DAT, cpfile, and sufile root metadata files.  Inodes of
 * these files are written in super root block instead of ifile, and
 * garbage collector doesn't keep any past versions of these files.
 */
#define NILFS_ROOT_METADATA_FILE(ino) \
	((ino) >= NILFS_DAT_INO && (ino) <= NILFS_SUFILE_INO)

/*
 * bytes offset of secondary super block
 */
#define NILFS_SB2_OFFSET_BYTES(devsize)	((((devsize) >> 12) - 1) << 12)

/*
 * Maximal count of links to a file
 */
#define NILFS_LINK_MAX		32000

/*
 * Structure of a directory entry
 *  (Same as ext2)
 */

#define NILFS_NAME_LEN 255

/*
 * Block size limitations
 */
#define NILFS_MIN_BLOCK_SIZE		1024
#define NILFS_MAX_BLOCK_SIZE		65536

/*
 * The new version of the directory entry.  Since V0 structures are
 * stored in intel byte order, and the name_len field could never be
 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 * file_type field.
 */
struct nilfs_dir_entry {
	__le64	inode;			/* Inode number */
	__le16	rec_len;		/* Directory entry length */
	__u8	name_len;		/* Name length */
	__u8	file_type;		/* Dir entry type (file, dir, etc) */
	char	name[NILFS_NAME_LEN];	/* File name */
	char    pad;
};

/*
 * NILFS directory file types.  Only the low 3 bits are used.  The
 * other bits are reserved for now.
 */
enum {
	NILFS_FT_UNKNOWN,
	NILFS_FT_REG_FILE,
	NILFS_FT_DIR,
	NILFS_FT_CHRDEV,
	NILFS_FT_BLKDEV,
	NILFS_FT_FIFO,
	NILFS_FT_SOCK,
	NILFS_FT_SYMLINK,
	NILFS_FT_MAX
};

/*
 * NILFS_DIR_PAD defines the directory entries boundaries
 *
 * NOTE: It must be a multiple of 8
 */
#define NILFS_DIR_PAD			8
#define NILFS_DIR_ROUND			(NILFS_DIR_PAD - 1)
#define NILFS_DIR_REC_LEN(name_len)	(((name_len) + 12 + NILFS_DIR_ROUND) & \
					~NILFS_DIR_ROUND)
#define NILFS_MAX_REC_LEN		((1 << 16) - 1)

/**
 * struct nilfs_finfo - file information
 * @fi_ino: inode number
 * @fi_cno: checkpoint number
 * @fi_nblocks: number of blocks (including intermediate blocks)
 * @fi_ndatablk: number of file data blocks
 */
struct nilfs_finfo {
	__le64 fi_ino;
	__le64 fi_cno;
	__le32 fi_nblocks;
	__le32 fi_ndatablk;
};

/**
 * struct nilfs_binfo_v - information on a data block (except DAT)
 * @bi_vblocknr: virtual block number
 * @bi_blkoff: block offset
 */
struct nilfs_binfo_v {
	__le64 bi_vblocknr;
	__le64 bi_blkoff;
};

/**
 * struct nilfs_binfo_dat - information on a DAT node block
 * @bi_blkoff: block offset
 * @bi_level: level
 * @bi_pad: padding
 */
struct nilfs_binfo_dat {
	__le64 bi_blkoff;
	__u8 bi_level;
	__u8 bi_pad[7];
};

/**
 * union nilfs_binfo: block information
 * @bi_v: nilfs_binfo_v structure
 * @bi_dat: nilfs_binfo_dat structure
 */
union nilfs_binfo {
	struct nilfs_binfo_v bi_v;
	struct nilfs_binfo_dat bi_dat;
};

/**
 * struct nilfs_segment_summary - segment summary header
 * @ss_datasum: checksum of data
 * @ss_sumsum: checksum of segment summary
 * @ss_magic: magic number
 * @ss_bytes: size of this structure in bytes
 * @ss_flags: flags
 * @ss_seq: sequence number
 * @ss_create: creation timestamp
 * @ss_next: next segment
 * @ss_nblocks: number of blocks
 * @ss_nfinfo: number of finfo structures
 * @ss_sumbytes: total size of segment summary in bytes
 * @ss_pad: padding
 * @ss_cno: checkpoint number
 */
struct nilfs_segment_summary {
	__le32 ss_datasum;
	__le32 ss_sumsum;
	__le32 ss_magic;
	__le16 ss_bytes;
	__le16 ss_flags;
	__le64 ss_seq;
	__le64 ss_create;
	__le64 ss_next;
	__le32 ss_nblocks;
	__le32 ss_nfinfo;
	__le32 ss_sumbytes;
	__le32 ss_pad;
	__le64 ss_cno;
	/* array of finfo structures */
};

#define NILFS_SEGSUM_MAGIC	0x1eaffa11  /* segment summary magic number */

/*
 * Segment summary flags
 */
#define NILFS_SS_LOGBGN 0x0001  /* begins a logical segment */
#define NILFS_SS_LOGEND 0x0002  /* ends a logical segment */
#define NILFS_SS_SR     0x0004  /* has super root */
#define NILFS_SS_SYNDT  0x0008  /* includes data only updates */
#define NILFS_SS_GC     0x0010  /* segment written for cleaner operation */

/**
 * struct nilfs_btree_node - header of B-tree node block
 * @bn_flags: flags
 * @bn_level: level
 * @bn_nchildren: number of children
 * @bn_pad: padding
 */
struct nilfs_btree_node {
	__u8 bn_flags;
	__u8 bn_level;
	__le16 bn_nchildren;
	__le32 bn_pad;
};

/* flags */
#define NILFS_BTREE_NODE_ROOT   0x01

/* level */
#define NILFS_BTREE_LEVEL_DATA          0
#define NILFS_BTREE_LEVEL_NODE_MIN      (NILFS_BTREE_LEVEL_DATA + 1)
#define NILFS_BTREE_LEVEL_MAX           14	/* Max level (exclusive) */

/**
 * struct nilfs_direct_node - header of built-in bmap array
 * @dn_flags: flags
 * @dn_pad: padding
 */
struct nilfs_direct_node {
	__u8 dn_flags;
	__u8 pad[7];
};

/**
 * struct nilfs_palloc_group_desc - block group descriptor
 * @pg_nfrees: number of free entries in block group
 */
struct nilfs_palloc_group_desc {
	__le32 pg_nfrees;
};

/**
 * struct nilfs_dat_entry - disk address translation entry
 * @de_blocknr: block number
 * @de_start: start checkpoint number
 * @de_end: end checkpoint number
 * @de_rsv: reserved for future use
 */
struct nilfs_dat_entry {
	__le64 de_blocknr;
	__le64 de_start;
	__le64 de_end;
	__le64 de_rsv;
};

#define NILFS_MIN_DAT_ENTRY_SIZE	32

/**
 * struct nilfs_snapshot_list - snapshot list
 * @ssl_next: next checkpoint number on snapshot list
 * @ssl_prev: previous checkpoint number on snapshot list
 */
struct nilfs_snapshot_list {
	__le64 ssl_next;
	__le64 ssl_prev;
};

/**
 * struct nilfs_checkpoint - checkpoint structure
 * @cp_flags: flags
 * @cp_checkpoints_count: checkpoints count in a block
 * @cp_snapshot_list: snapshot list
 * @cp_cno: checkpoint number
 * @cp_create: creation timestamp
 * @cp_nblk_inc: number of blocks incremented by this checkpoint
 * @cp_inodes_count: inodes count
 * @cp_blocks_count: blocks count
 * @cp_ifile_inode: inode of ifile
 */
struct nilfs_checkpoint {
	__le32 cp_flags;
	__le32 cp_checkpoints_count;
	struct nilfs_snapshot_list cp_snapshot_list;
	__le64 cp_cno;
	__le64 cp_create;
	__le64 cp_nblk_inc;
	__le64 cp_inodes_count;
	__le64 cp_blocks_count;

	/*
	 * Do not change the byte offset of ifile inode.
	 * To keep the compatibility of the disk format,
	 * additional fields should be added behind cp_ifile_inode.
	 */
	struct nilfs_inode cp_ifile_inode;
};

#define NILFS_MIN_CHECKPOINT_SIZE	(64 + NILFS_MIN_INODE_SIZE)

/* checkpoint flags */
enum {
	NILFS_CHECKPOINT_SNAPSHOT,
	NILFS_CHECKPOINT_INVALID,
	NILFS_CHECKPOINT_SKETCH,
	NILFS_CHECKPOINT_MINOR,
};

#define NILFS_CHECKPOINT_FNS(flag, name)				\
static inline void							\
nilfs_checkpoint_set_##name(struct nilfs_checkpoint *cp)		\
{									\
	cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) |	\
				     (1UL << NILFS_CHECKPOINT_##flag));	\
}									\
static inline void							\
nilfs_checkpoint_clear_##name(struct nilfs_checkpoint *cp)		\
{									\
	cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) &	\
				   ~(1UL << NILFS_CHECKPOINT_##flag));	\
}									\
static inline int							\
nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp)		\
{									\
	return !!(__le32_to_cpu(cp->cp_flags) &				\
		  (1UL << NILFS_CHECKPOINT_##flag));			\
}

NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot)
NILFS_CHECKPOINT_FNS(INVALID, invalid)
NILFS_CHECKPOINT_FNS(MINOR, minor)

/**
 * struct nilfs_cpfile_header - checkpoint file header
 * @ch_ncheckpoints: number of checkpoints
 * @ch_nsnapshots: number of snapshots
 * @ch_snapshot_list: snapshot list
 */
struct nilfs_cpfile_header {
	__le64 ch_ncheckpoints;
	__le64 ch_nsnapshots;
	struct nilfs_snapshot_list ch_snapshot_list;
};

#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET				\
	((sizeof(struct nilfs_cpfile_header) +				\
	  sizeof(struct nilfs_checkpoint) - 1) /			\
			sizeof(struct nilfs_checkpoint))

/**
 * struct nilfs_segment_usage - segment usage
 * @su_lastmod: last modified timestamp
 * @su_nblocks: number of blocks in segment
 * @su_flags: flags
 */
struct nilfs_segment_usage {
	__le64 su_lastmod;
	__le32 su_nblocks;
	__le32 su_flags;
};

#define NILFS_MIN_SEGMENT_USAGE_SIZE	16

/* segment usage flag */
enum {
	NILFS_SEGMENT_USAGE_ACTIVE,
	NILFS_SEGMENT_USAGE_DIRTY,
	NILFS_SEGMENT_USAGE_ERROR,
};

#define NILFS_SEGMENT_USAGE_FNS(flag, name)				\
static inline void							\
nilfs_segment_usage_set_##name(struct nilfs_segment_usage *su)		\
{									\
	su->su_flags = __cpu_to_le32(__le32_to_cpu(su->su_flags) |	\
				   (1UL << NILFS_SEGMENT_USAGE_##flag));\
}									\
static inline void							\
nilfs_segment_usage_clear_##name(struct nilfs_segment_usage *su)	\
{									\
	su->su_flags =							\
		__cpu_to_le32(__le32_to_cpu(su->su_flags) &		\
			    ~(1UL << NILFS_SEGMENT_USAGE_##flag));      \
}									\
static inline int							\
nilfs_segment_usage_##name(const struct nilfs_segment_usage *su)	\
{									\
	return !!(__le32_to_cpu(su->su_flags) &				\
		  (1UL << NILFS_SEGMENT_USAGE_##flag));			\
}

NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
NILFS_SEGMENT_USAGE_FNS(ERROR, error)

static inline void
nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su)
{
	su->su_lastmod = __cpu_to_le64(0);
	su->su_nblocks = __cpu_to_le32(0);
	su->su_flags = __cpu_to_le32(0);
}

static inline int
nilfs_segment_usage_clean(const struct nilfs_segment_usage *su)
{
	return !__le32_to_cpu(su->su_flags);
}

/**
 * struct nilfs_sufile_header - segment usage file header
 * @sh_ncleansegs: number of clean segments
 * @sh_ndirtysegs: number of dirty segments
 * @sh_last_alloc: last allocated segment number
 */
struct nilfs_sufile_header {
	__le64 sh_ncleansegs;
	__le64 sh_ndirtysegs;
	__le64 sh_last_alloc;
	/* ... */
};

#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET				\
	((sizeof(struct nilfs_sufile_header) +				\
	  sizeof(struct nilfs_segment_usage) - 1) /			\
			 sizeof(struct nilfs_segment_usage))

#endif	/* _LINUX_NILFS2_ONDISK_H */